Twelve years before that, however, Mustaine suffered severe radial nerve damage that extensively damaged his left arm. His radial neuropathy was the result of falling asleep with his arm over the back of a chair; he was told by doctors that he might get 80 percent of his movement back—but that he’d never play guitar again.

That didn’t fly with Mustaine; he went through nearly 18 months of painful therapy and got himself back on stage by 2004.

Back in 2002, at the time of theradial neuropathy, Megadeth were playing a run of Big Four shows with Metallica, Slayer and Anthrax; Mustaine almost missed the New York City show, but things worked out.

Recently, Mustaine was discussing the 2014 surgery with the South China Morning Post; during the interview, he admitted the damage to his left hand is still—very much so—an issue.

“The hardest thing was not headbanging—I just do it without thinking,” he said. “You don’t know what it’s like to be in my body. There are some days when my left hand can’t even play. I don’t practice. I save it all for the tour.”